Solar Domestic Water Heater
The fast lane to clean energy

Solar Domestic Water Heater Basics

The solar domestic water heater provides a cost effective solution to the residential water heating requirements

A modern home uses hot and warm water for bathing, showers, dish washing and clothes washing. The energy consumed on heating water amounts to 25%-40% of the total household energy consumption. Shopping and installing a residential solar water heater requires a modest budget of $1,500 to $3,500. The price is dependent on the solar water heating type and the solar water heating size. Energy tax credit plans provide federal tax credit of 30%, additional energy tax credits are available in most of the States. A solar thermal water heater is mature and cost effective and the pay back time is 2-4 years, granting additional 8-10 years of free of charge residential hot water supply.

Principle of Operation

A solar hot water collector absorbs sun radiation in the visible wavelength and heats up liquid (water or glycol). The liquid flows in a loop to a storage tank where hot water are stored and the cooler liquid returns to the collector. In most cases, a backup heater is needed for cloudy days, one can use his existing water heater for backup or have the backup heater installed in the hot water storage tank

Other Components

For active solar water heaters a solar water pump is needed. If glycol is used a heat exchanger is installed in the storage tank. Other components are a thermostat, valves and plumbing.

Passive Solar Water Heaters

In warm zones such as the Sun Belt states where temperatures are always above freezing and if the tank can be installed above the collector, the most simple passive solar domestic water heater can be used. This system consists of only a storage tank and a collector and it is a direct system (water only). It is the lowest price system available

Installation and Maintenance

The water heater system can be installed as a turn key project by a solar contractor or to be self installed (DIY)

With no moving parts (except for the pump), the required maintenance is very low, the life expectancy of the solar hot water heater can be well above 10 years if it gets the proper care